Melissa Kennedy, DVM, PhD, DACVM

FIP – nothing's ever simple....It is a multifactoral disease involving virus factors, host factors, and environmental factors. The virus of FIP is feline coronavirus (FCoV) – interestingly, it is required but not sufficient for FIP. Coronaviruses have a large RNA genome.

The primary role of the immune system is to protect against infectious disease. The mechanisms employed vary in efficiency for intra- vs extracellular pathogens. Nonspecific immunologic resistance involves interferon – stimulates production of proteins with antiviral activity.

Immunoprophylaxis is the enhancement of a specific immune response to the specific pathogen. Humoral and cell-mediated immune response are critical to effective immunity. This response is induced by microbes, their components or by-products. The majority of vaccines prevent infectious disease, but not infection.

An outbreak of respiratory disease occurred in a kennel of racing greyhounds in 2004. While some dogs exhibited mild disease with fever and cough, some experienced peracute death with pulmonary hemorrhage (case fatality 36%). Virologic analysis revealed an influenza virus that was later found to be closely related to equine influenza virus subtype H3N8, sharing >96% genetic sequence identity.

The immune system has two arms of defense, nonspecific and specific. As with the immune system in total, there are many elements of the nonspecific arm of the immune response. These have in common their lack of strict recognition of foreign material and absence of memory.

Immunology plays a huge role in diagnostics for infectious diseases. In addition, various assays are able to assess the immune system itself in an animal.